//src/APP.vue

<template>
<div id="conditional-rendering">
  <span v-if="seen">现在你看到我了</span>
</div>
</template>

<script lang="ts">
import { ref, defineComponent } from "vue"


export default defineComponent({
  name: 'App',
  setup() {
    const seen = ref(true)
    return {
      seen
    }
  }
}) 
</script>